feat: update some contracts to use solidity 0.8

.solcover.js

@@ -7,4 +7,5 @@ module.exports = {
   },
   skipFiles,
   istanbulFolder: './reports/coverage',
+  configureYulOptimizer: true,
 }

contracts/arbitrum/AddressAliasHelper.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/84e64dee6ee82adbf8ec34fd4b86c207a61d9007/packages/arb-bridge-eth
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
- *
+ * - Changed solidity version to >=0.8.0 <0.9.0  ([email protected])
+ * - Added an unchecked to the alias calculation to work on 0.8
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.8.0 <0.9.0;
 
 library AddressAliasHelper {
     uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);
@@ -33,14 +33,18 @@ library AddressAliasHelper {
     /// @param l1Address the address in the L1 that triggered the tx to L2
     /// @return l2Address L2 address as viewed in msg.sender
     function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
-        l2Address = address(uint160(l1Address) + offset);
+        unchecked {
+            l2Address = address(uint160(l1Address) + offset);
+        }
     }
 
     /// @notice Utility function that converts the msg.sender viewed in the L2 to the
     /// address in the L1 that submitted a tx to the inbox
     /// @param l2Address L2 address as viewed in msg.sender
     /// @return l1Address the address in the L1 that triggered the tx to L2
     function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
-        l1Address = address(uint160(l2Address) - offset);
+        unchecked {
+            l1Address = address(uint160(l2Address) - offset);
+        }
     }
 }

contracts/arbitrum/IArbToken.sol

@@ -19,15 +19,15 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-peripherals
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
 /**
  * @title Minimum expected interface for L2 token that interacts with the L2 token bridge (this is the interface necessary
  * for a custom token that interacts with the bridge, see TestArbCustomToken.sol for an example implementation).
  */
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 interface IArbToken {
     /**

contracts/arbitrum/IBridge.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-eth
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 interface IBridge {
     event MessageDelivered(

contracts/arbitrum/IInbox.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-eth
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 import "./IBridge.sol";
 import "./IMessageProvider.sol";

contracts/arbitrum/IMessageProvider.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-eth
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 interface IMessageProvider {
     event InboxMessageDelivered(uint256 indexed messageNum, bytes data);

contracts/arbitrum/IOutbox.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-eth
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 interface IOutbox {
     event OutboxEntryCreated(

contracts/arbitrum/ITokenGateway.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-peripherals
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 interface ITokenGateway {
     /// @notice event deprecated in favor of DepositInitiated and WithdrawalInitiated

contracts/arbitrum/L1ArbitrumMessenger.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-peripherals
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 import "./IInbox.sol";
 import "./IOutbox.sol";

contracts/arbitrum/L2ArbitrumMessenger.sol

@@ -19,11 +19,11 @@
  * https://github.com/OffchainLabs/arbitrum/tree/e3a6307ad8a2dc2cad35728a2a9908cfd8dd8ef9/packages/arb-bridge-peripherals
  *
  * MODIFIED from Offchain Labs' implementation:
- * - Changed solidity version to 0.7.6 ([email protected])
+ * - Changed solidity version to >=0.7.0 <0.9.0 ([email protected])
  *
  */
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.7.0 <0.9.0;
 
 import "arbos-precompiles/arbos/builtin/ArbSys.sol";
 

contracts/arbitrum/README.md

@@ -2,4 +2,4 @@
 
 These contracts have been copied from the [Arbitrum repo](https://github.com/OffchainLabs/arbitrum).
 
-They are also available as part of the npm packages [arb-bridge-eth](https://www.npmjs.com/package/arb-bridge-eth) and [arb-bridge-peripherals](https://www.npmjs.com/package/arb-bridge-peripherals). The reason for copying them rather than installing those packages is the contracts only support Solidity `^0.6.11`, so we had to change the version to `^0.7.6` for it to be compatible with our other contracts.
+They are also available as part of the npm packages [arb-bridge-eth](https://www.npmjs.com/package/arb-bridge-eth) and [arb-bridge-peripherals](https://www.npmjs.com/package/arb-bridge-peripherals). The reason for copying them rather than installing those packages is the contracts only support Solidity `^0.6.11`, so we had to change the version to `>=0.7.0 <0.9.0` for it to be compatible with our other contracts.

contracts/bancor/BancorFormula.sol

@@ -1,12 +1,8 @@
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity ^0.7.6;
-
-import "@openzeppelin/contracts/math/SafeMath.sol";
+pragma solidity ^0.8.16;
 
 contract BancorFormula {
-    using SafeMath for uint256;
-
     uint16 public constant version = 6;
 
     uint256 private constant ONE = 1;
@@ -199,13 +195,13 @@ contract BancorFormula {
         if (_depositAmount == 0) return 0;
 
         // special case if the ratio = 100%
-        if (_reserveRatio == MAX_RATIO) return _supply.mul(_depositAmount) / _reserveBalance;
+        if (_reserveRatio == MAX_RATIO) return (_supply * _depositAmount) / _reserveBalance;
 
         uint256 result;
         uint8 precision;
-        uint256 baseN = _depositAmount.add(_reserveBalance);
+        uint256 baseN = _depositAmount + _reserveBalance;
         (result, precision) = power(baseN, _reserveBalance, _reserveRatio, MAX_RATIO);
-        uint256 temp = _supply.mul(result) >> precision;
+        uint256 temp = (_supply * result) >> precision;
         return temp - _supply;
     }
 
@@ -246,13 +242,13 @@ contract BancorFormula {
         if (_sellAmount == _supply) return _reserveBalance;
 
         // special case if the ratio = 100%
-        if (_reserveRatio == MAX_RATIO) return _reserveBalance.mul(_sellAmount) / _supply;
+        if (_reserveRatio == MAX_RATIO) return (_reserveBalance * _sellAmount) / _supply;
 
         uint256 result;
         uint8 precision;
         uint256 baseD = _supply - _sellAmount;
         (result, precision) = power(_supply, baseD, MAX_RATIO, _reserveRatio);
-        uint256 temp1 = _reserveBalance.mul(result);
+        uint256 temp1 = _reserveBalance * result;
         uint256 temp2 = _reserveBalance << precision;
         return (temp1 - temp2) / result;
     }
@@ -292,13 +288,13 @@ contract BancorFormula {
 
         // special case for equal ratios
         if (_fromReserveRatio == _toReserveRatio)
-            return _toReserveBalance.mul(_amount) / _fromReserveBalance.add(_amount);
+            return (_toReserveBalance * _amount) / (_fromReserveBalance + _amount);
 
         uint256 result;
         uint8 precision;
-        uint256 baseN = _fromReserveBalance.add(_amount);
+        uint256 baseN = _fromReserveBalance + _amount;
         (result, precision) = power(baseN, _fromReserveBalance, _fromReserveRatio, _toReserveRatio);
-        uint256 temp1 = _toReserveBalance.mul(result);
+        uint256 temp1 = _toReserveBalance * result;
         uint256 temp2 = _toReserveBalance << precision;
         return (temp1 - temp2) / result;
     }
@@ -332,13 +328,13 @@ contract BancorFormula {
         if (_amount == 0) return 0;
 
         // special case if the total ratio = 100%
-        if (_totalRatio == MAX_RATIO) return (_amount.mul(_reserveBalance) - 1) / _supply + 1;
+        if (_totalRatio == MAX_RATIO) return ((_amount * _reserveBalance) - 1) / _supply + 1;
 
         uint256 result;
         uint8 precision;
-        uint256 baseN = _supply.add(_amount);
+        uint256 baseN = _supply + _amount;
         (result, precision) = power(baseN, _supply, MAX_RATIO, _totalRatio);
-        uint256 temp = ((_reserveBalance.mul(result) - 1) >> precision) + 1;
+        uint256 temp = (((_reserveBalance * result) - 1) >> precision) + 1;
         return temp - _reserveBalance;
     }
 
@@ -378,13 +374,13 @@ contract BancorFormula {
         if (_amount == _supply) return _reserveBalance;
 
         // special case if the total ratio = 100%
-        if (_totalRatio == MAX_RATIO) return _amount.mul(_reserveBalance) / _supply;
+        if (_totalRatio == MAX_RATIO) return (_amount * _reserveBalance) / _supply;
 
         uint256 result;
         uint8 precision;
         uint256 baseD = _supply - _amount;
         (result, precision) = power(_supply, baseD, MAX_RATIO, _totalRatio);
-        uint256 temp1 = _reserveBalance.mul(result);
+        uint256 temp1 = _reserveBalance * result;
         uint256 temp2 = _reserveBalance << precision;
         return (temp1 - temp2) / result;
     }

contracts/base/IMulticall.sol

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
-pragma abicoder v2;
+pragma solidity >=0.7.0 <0.9.0;
 
 /**
  * @title Multicall interface

contracts/base/Multicall.sol

@@ -1,9 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
-pragma abicoder v2;
+pragma solidity ^0.8.16;
 
-import "./IMulticall.sol";
+import { IMulticall } from "./IMulticall.sol";
 
 // Inspired by https://github.com/Uniswap/uniswap-v3-periphery/blob/main/contracts/base/Multicall.sol
 // Note: Removed payable from the multicall

contracts/curation/Curation.sol

@@ -1,18 +1,20 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity ^0.8.16;
 
-import "@openzeppelin/contracts/utils/Address.sol";
-import "@openzeppelin/contracts/math/SafeMath.sol";
-import "@openzeppelin/contracts/proxy/Clones.sol";
+import { Address } from "@openzeppelin/contracts/utils/Address.sol";
+import { Clones } from "@openzeppelin/contracts/proxy/Clones.sol";
 
-import "../bancor/BancorFormula.sol";
-import "../upgrades/GraphUpgradeable.sol";
-import "../utils/TokenUtils.sol";
+import { BancorFormula } from "../bancor/BancorFormula.sol";
+import { GraphUpgradeable } from "../upgrades/GraphUpgradeable.sol";
+import { TokenUtils } from "../utils/TokenUtils.sol";
 
-import "./CurationStorage.sol";
-import "./ICuration.sol";
-import "./GraphCurationToken.sol";
+import { CurationV1Storage } from "./CurationStorage.sol";
+import { ICuration } from "./ICuration.sol";
+import { IGraphCurationToken } from "./IGraphCurationToken.sol";
+import { IRewardsManager } from "../rewards/IRewardsManager.sol";
+import { Managed } from "../governance/Managed.sol";
+import { IGraphToken } from "../token/IGraphToken.sol";
 
 /**
  * @title Curation contract
@@ -27,8 +29,6 @@ import "./GraphCurationToken.sol";
  * bonding curve.
  */
 contract Curation is CurationV1Storage, GraphUpgradeable {
-    using SafeMath for uint256;
-
     // 100% in parts per million
     uint32 private constant MAX_PPM = 1000000;
 
@@ -202,7 +202,7 @@ contract Curation is CurationV1Storage, GraphUpgradeable {
 
         // Collect new funds into reserve
         CurationPool storage curationPool = pools[_subgraphDeploymentID];
-        curationPool.tokens = curationPool.tokens.add(_tokens);
+        curationPool.tokens = curationPool.tokens + _tokens;
 
         emit Collected(_subgraphDeploymentID, _tokens);
     }
@@ -256,7 +256,7 @@ contract Curation is CurationV1Storage, GraphUpgradeable {
         TokenUtils.burnTokens(_graphToken, curationTax);
 
         // Update curation pool
-        curationPool.tokens = curationPool.tokens.add(_tokensIn.sub(curationTax));
+        curationPool.tokens = curationPool.tokens + (_tokensIn - curationTax);
         curationPool.gcs.mint(curator, signalOut);
 
         emit Signalled(curator, _subgraphDeploymentID, _tokensIn, signalOut, curationTax);
@@ -297,7 +297,7 @@ contract Curation is CurationV1Storage, GraphUpgradeable {
 
         // Update curation pool
         CurationPool storage curationPool = pools[_subgraphDeploymentID];
-        curationPool.tokens = curationPool.tokens.sub(tokensOut);
+        curationPool.tokens = curationPool.tokens - tokensOut;
         curationPool.gcs.burnFrom(curator, _signalIn);
 
         // If all signal burnt delete the curation pool except for the
@@ -382,8 +382,8 @@ contract Curation is CurationV1Storage, GraphUpgradeable {
         override
         returns (uint256, uint256)
     {
-        uint256 curationTax = _tokensIn.mul(uint256(curationTaxPercentage)).div(MAX_PPM);
-        uint256 signalOut = _tokensToSignal(_subgraphDeploymentID, _tokensIn.sub(curationTax));
+        uint256 curationTax = (_tokensIn * uint256(curationTaxPercentage)) / MAX_PPM;
+        uint256 signalOut = _tokensToSignal(_subgraphDeploymentID, _tokensIn - curationTax);
         return (signalOut, curationTax);
     }
 
@@ -408,14 +408,12 @@ contract Curation is CurationV1Storage, GraphUpgradeable {
                 "Curation deposit is below minimum required"
             );
             return
-                BancorFormula(bondingCurve)
-                    .calculatePurchaseReturn(
-                        SIGNAL_PER_MINIMUM_DEPOSIT,
-                        minimumCurationDeposit,
-                        defaultReserveRatio,
-                        _tokensIn.sub(minimumCurationDeposit)
-                    )
-                    .add(SIGNAL_PER_MINIMUM_DEPOSIT);
+                BancorFormula(bondingCurve).calculatePurchaseReturn(
+                    SIGNAL_PER_MINIMUM_DEPOSIT,
+                    minimumCurationDeposit,
+                    defaultReserveRatio,
+                    _tokensIn - minimumCurationDeposit
+                ) + SIGNAL_PER_MINIMUM_DEPOSIT;
         }
 
         return

contracts/curation/CurationStorage.sol

@@ -1,8 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity ^0.8.16;
 
-import "../governance/Managed.sol";
+import { Managed } from "../governance/Managed.sol";
+import { ICuration } from "./ICuration.sol";
+import { IGraphCurationToken } from "./IGraphCurationToken.sol";
 
 abstract contract CurationV1Storage is Managed, ICuration {
     // -- Pool --